Background: Haishou Island in Nanhai District, Foshan City, is a river island in the Xijiang River. It is powered by a single 10kV transmission line that has been in operation for 17 years. During severe weather, repair crews face restricted access to the island.

User Profile: 1,473 households live on the island, primarily engaged in aquaculture fish farming. The aerators in the fish ponds require extremely high power supply reliability.

Pain Point: When the main transmission line fails, fish farmers face the risk of oxygen depletion in their ponds. The traditional solution of installing a second transmission line (via submarine cable) would require an investment as high as RMB 46.49 million, with complex approvals making it difficult to realize.

Solution:

• 1、Configuration: 2.1MW distributed PV + 2.15MW / 3.865MWh energy storage, all connected to the low-voltage grid

• 2、Strategy: Low-carbon power supply during normal conditions, emergency backup during disasters. When the main transmission line fails, the system can operate in "island mode" — providing 3 hours of support for critical loads and 25 hours of support for residential power needs.

Results:

• 1、Total investment of only RMB 9.72 million, far lower than the RMB 46.49 million required for the traditional approach

• 2、Provides a second "power lifeline" for island residents

• 3、The project has become a green energy model for Guangdong Province's "Hundreds, Thousands, Tens of Thousands Project"